48
Fig. 4.7
Types of client authentication at connection to the server modem
The
iRZ protocol-based
authentication is designed for the cases when the ATM client modem or iRZ proto-
col-enabled software, is installed in the dispatching center. The iRZ protocol-based authentication is imple-
mented by the GPRS password or by the login
– GPRS password pair. The right to connect to the server mo-
dem is not provided for each client, but only for one which has a valid GPRS password or the login
– GPRS
password pair (depending on the server modem settings). This means that their values, specified in the settings
of a connected client, must coincide with those specified in the server modem settings.
At authentication
by
GPRS password
: if a new client tries to connect to the modem, and there has been no
data or keepalive packets communication with a current client within a minute, operating connection to the cur-
rent client is terminated and connection to a new client is established. Operation with the current client contin-
ues in a different way.
At authentication by
login and GPRS password
: if a new client tries to connect to the modem and its login
and password are valid, the modem establishes operating connection to a new client and terminates the previ-
ous connection. If the login and password do not match, the server modem continues to operate with the previ-
ous client.
IP address authentication is used when the client holds a public static IP address (when renting APN from
the mobile network carrier
– a private static IP address); the clients with other IP addresses fail to operate with
the server modem.
At authentication
by IP address
: An IP address of the connecting client is compared with the IP address set
in the server modem settings. If the address matches, connection to a new client becomes operational and the
previous connection is terminated. If not, the server modem continues its operation with the previous client.
Without authentication mechanism:
when the modem is already working with the current client, and a new
client is trying to connect the modem at the same time, 2 options are possible:
If data has been transmitted within the last minute, operation with the current client proceeds. In this case
connection of a new client is terminated.
If data has not been transmitted within a minute, connection to a current client is terminated, and connec-
tion to a new connected client is established.
